Dear All,

from what it looks like the memory mapped io classes in boost::interprocess cannot deal with readonly files.

This is a big problem.

I think opening readonly files should be possible but all write operations to the file should fail.

Of course mapping a readonly file should be done with the matching flags so that the mapping can be shared and that the matching address space is readonly.

Also another drawback is that at least on Windows disk-space is being allocated when growing a file.

This is slow and it can be avoided by making the file sparse.

On UNIXs this is the default.

Thanks

Peter